Physics-Constrained Backdoor Attacks on Power System Fault Localization

The advances in deep learning (DL) techniques have the potential to deliver transformative technological breakthroughs to numerous complex tasks in modern power systems that suffer from increasing uncertainty and nonlinearity. However, the vulnerability of DL has yet to be thoroughly explored in power system tasks under various physical constraints. This work, for the first time, proposes a novel physics-constrained backdoor poisoning attack, which embeds the undetectable attack signal into the learned model and only performs the attack when it encounters the corresponding signal. The paper illustrates the proposed attack on the real-time fault line localization application. Furthermore, the simulation results on the 68-bus power system demonstrate that DL-based fault line localization methods are not robust to our proposed attack, indicating that backdoor poisoning attacks pose real threats to DL implementations in power systems. The proposed attack pipeline can be easily generalized to other power system tasks

The association of long-term trajectories of BMI, its variability, and metabolic syndrome: a 30-year prospective cohort study

Background Limited data exists on how early-life weight changes relate to metabolic syndrome (MetS) risk in midlife. This study examines the association between long-term trajectories of body mass index (BMI), its variability, and MetS risk in Chinese individuals. Methods In the Hanzhong Adolescent Hypertension study (March 10, 1987–June 3, 2017), 1824 participants with at least five BMI measurements from 1987 to 2017 were included. Using group-based trajectory modeling, different BMI trajectories were identified. BMI variability was assessed through standard deviation (SD), variability independent of the mean (VIM), and average real variability (ARV). Logistic regression analyzed the relationship between BMI trajectory, BMI variability, and MetS occurrence in midlife (URL: https://www.clinicaltrials.gov; Unique identifier: NCT02734472). Findings BMI trajectories were categorized as low-increasing (34.4%), moderate-increasing (51.8%), and high-increasing (13.8%). Compared to the low-increasing group, the odds ratios (ORs) [95% CIs] for MetS were significantly higher in moderate (4.27 [2.63–6.91]) and high-increasing groups (13.11 [6.30–27.31]) in fully adjusted models. Additionally, higher BMI variabilities were associated with increased MetS odds (ORs for SDBMI, VIMBMI, and ARVBMI: 2.30 [2.02–2.62], 1.22 [1.19–1.26], and 4.29 [3.38–5.45]). Furthermore, BMI trajectories from childhood to adolescence were predictive of midlife MetS, with ORs in moderate (1.49 [1.00–2.23]) and high-increasing groups (2.45 [1.22–4.91]). Lastly, elevated BMI variability in this period was also linked to higher MetS odds (ORs for SDBMI, VIMBMI, and ARVBMI: 1.24 [1.08–1.42], 1.00 [1.00–1.01], and 1.21 [1.05–1.38]). Interpretation Our study suggests that both early-life BMI trajectories and BMI variability could be predictive of incident MetS in midlife

The Survey of H5N1 Flu Virus in Wild Birds in 14 Provinces of China from 2004 to 2007

The highly pathogenic H5N1 avian influenza emerged in the year 1996 in Asia, and has spread to Europe and Africa recently. At present, effective monitoring and data analysis of H5N1 are not sufficient in Chinese mainland.)) were obviously higher than those in other 13 provinces. The results of sequence analysis indicated that the 17 strains isolated from wild birds were distributed in five clades (2.3.1, 2.2, 2.5, 6, and 7), which suggested that genetic diversity existed among H5N1 viruses isolated from wild birds. The five isolates from Qinghai came from one clade (2.2) and had a short evolutionary distance with the isolates obtained from Qinghai in the year 2005.We have measured the prevalence of H5N1 virus in 56 species of wild birds in 14 provinces of China. Continuous monitoring in the field should be carried out to know whether H5N1 virus can be maintained by wild birds

Potassium supplementation ameliorates increased plasma homocysteine induced by salt loading in normotensive salt-sensitive subjects

The mechanism by which high-salt and low-potassium diet contributes to hypertension remains poorly understood. Plasma homocysteine (Hcys) is recognized as a primary mediator of blood pressure (BP) response to some diets. Therefore, the present study tried to investigate whether plasma Hcys and BP could be regulated by salt loading in normotensive salt-sensitive (SS) persons, and further explored whether potassium supplementation could reverse the effect. We enrolled 47 normotensive subjects, aged 29–65 years. The protocol included 7 days on a low-salt diet (3g/day, NaCl), 7 days on a high-salt diet (18g/day), and then a high-salt diet with potassium supplementation (4.5g/day) for 7 days. After high-salt intake, BP was significantly increased and potassium supplementation lowered it in the SS group. Plasma Hcys were higher in SS subjects than in salt-resistant (SR) subjects after salt loading (34.4 ± 17.0 μmol/L versus 19.16 ± 6.4 μmol/L, P < 0.01). Plasma Hcys in SS subjects was increased on a high-salt diet than on a low-salt diet (34.4 ± 17.0 μmol/L versus 16.5 ± 8.3 μmol/L, P < 0.01), but plasma Hcys was ameliorated by potassium supplementation (34.4 ± 17.0 μmol/L versus 20.9 ± 10.4 μmol/L, P < 0.01). In SS subjects, the change of mean arterial blood pressure (MBP) correlated significantly and positively with the alteration of plasma Hcys during low-salt to high-salt intake and high-salt to high-salt with potassium supplementation (r = 0.75, P < 0.001; r = 0.74, P < 0.001, respectively). Our results indicate that Hcys may partly mediate the impact of high-salt intake and potassium supplementation on BP in SS subjects

Effects of once-weekly exenatide on cardiovascular outcomes in type 2 diabetes

BACKGROUND: The cardiovascular effects of adding once-weekly treatment with exenatide to usual care in patients with type 2 diabetes are unknown. METHODS: We randomly assigned patients with type 2 diabetes, with or without previous cardiovascular disease, to receive subcutaneous injections of extended-release exenatide at a dose of 2 mg or matching placebo once weekly. The primary composite outcome was the first occurrence of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. The coprimary hypotheses were that exenatide, administered once weekly, would be noninferior to placebo with respect to safety and superior to placebo with respect to efficacy. RESULTS: In all, 14,752 patients (of whom 10,782 [73.1%] had previous cardiovascular disease) were followed for a median of 3.2 years (interquartile range, 2.2 to 4.4). A primary composite outcome event occurred in 839 of 7356 patients (11.4%; 3.7 events per 100 person-years) in the exenatide group and in 905 of 7396 patients (12.2%; 4.0 events per 100 person-years) in the placebo group (hazard ratio, 0.91; 95% confidence interval [CI], 0.83 to 1.00), with the intention-to-treat analysis indicating that exenatide, administered once weekly, was noninferior to placebo with respect to safety (P<0.001 for noninferiority) but was not superior to placebo with respect to efficacy (P=0.06 for superiority). The rates of death from cardiovascular causes, fatal or nonfatal myocardial infarction, fatal or nonfatal stroke, hospitalization for heart failure, and hospitalization for acute coronary syndrome, and the incidence of acute pancreatitis, pancreatic cancer, medullary thyroid carcinoma, and serious adverse events did not differ significantly between the two groups. CONCLUSIONS: Among patients with type 2 diabetes with or without previous cardiovascular disease, the incidence of major adverse cardiovascular events did not differ significantly between patients who received exenatide and those who received placebo